Boiler plug



May 14, 1929. P. E. MclNTosH 1,713,345

BOILER PLUG Filed Feb. 19, 1926 Pf lNVENTbR A TTORNE Y5 Patented Ma 14, 1929.

.UNITEDFSTATES PETER 1a McINTOSH, or KALAMAZOO, MICHIGAN, ASSIGNOR or ONE-EIGHTH TO 1,713,345 PATENTOFFA'ICE.

CHARLES R. ALLEN, 0F KALAMAZOO, MICHIGAN.

BOILER PLUG.

Applicatiorfflled February 19, 1926.- Serial No. 89,367.

This invention relates to improvements in boiler plugs for locomotives, although the invention is adaptable to a great variety of uses. The invention is particularly an im provement and development of the boiler In {45 ,91'1, issued June 5, 1923, to myself and Russell OConnell. g

The object of the invention is to provide such a plug which is very secure and strong and which can be readily detached and removed. It is a special object to facilitate operation, improve the locking means and simplify the plugpart. Objects pertainin to details and economies ofconstruction an operation will appear from the detailed description to follow. The invention is clearly defined and pointed out in the claims.

A structure which is a preferred embodiment of the invention is illustrated in the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a side elevational view of my improved boiler plug structure in assembled position ready for the bushing to be inserted into the wall or plate of a boiler, taken looking onto the end'of the plug across bar.

Fig. 2 is an end elevation view of the structure appearing in Fig. 1, taken from the left hand end with the cross bar turned to vertical.

Fig. 3 is an end' elevation view of the right hand end of Fig. 1. I

Fig. 4 is ahorizontal sectional view, part of the plug being shown in full lines, taken on line 44 of Figs. 1,2 and 3, shown in place in a boiler plate or wall.

The parts of the drawing will be considered by their numbers, which identify like parts in all the views.

1 is a section of the boiler plate. 2 is the threaded bushing inserted'into the plate, the

. outer end 3 of which bushing is flat forming a bearing for the flange of the plug. The inner end of the bushing is divided into two oblique spiral surfaces 4, 4, there being longitudinal notches5, 5 separating these two oblique surfaces, and stop projections, 41 at the end of each spiral insure a full guide and turning in the right direction and prevent any pos sibility of turning the plug too far. The plug 6 is provided with an outwardlyprojecting collar-like flange 7 at its outer end having a bearing seat against the outer end 4 of the bushing. Back of this collar is an elof United States Letters Patent Noliptical annular groove or seat 7 1. The inner end of the plugfi is provided with a cross arm or oppositely-projecting lugs 8, 8 of such dimensions as to pass readily: through the longitudinal slots '5, .5, so that theyjmay bet'urned intoengagement with the: spiral surfaces4, .4 at the, innerend of'the bushing,

thus producing a joint similar to a bayonet" joint except that the oblique ends enable the tightening of the flange of the plug against the bushing. Correct manipulation is insured by the stops 41. A square projecting end 9 is provided on the outer end ofthe plug to enable the same to be turned into overhanging ear 11 which overhangs the end flange of the plugs. A set screw 12 fits into the screw hole 13 through the said ear to engage the periphery of the projecting end of the plug back of the flange 7 in the elliptical part 71 to lock the same against rotation.

It will thus be seen that the plug can be brought against its bearingsurface by very strong pressure by the, use of the wrench and that when the same is thus urged into position it may be very readily secured in that position by the set screw. The plug can be read ily removed by hand by simply releasing the set screw, a matter of advantage in the speedy handling of such structures, there being a large number of them on each locomotive.

The elliptical seat 71 for the set screw insures its effective seating and action, it being disposed in proper relation to the cross arm.

These plugs for use on locomotives are required to resist very high steam pressure and they must be adjusted very tightly and securely.

Having thus described my invention, what ear, a radially disposed set screw through said ear, and a one piece plug having a collar-like peripheral flange at its outer end faced on its inner-sideto'coact with said bearing seat of said bushing and having an elliptical seat outside of said flange for engagementby saidset screw, saidfplug having-opposed lugsat its inner end adapted to'be introducedthrough the said longitudinal grooves of said bushing into engagement with the said spiralsur-a 2. In a-boiler plug the combination with av one-piece externally-threaded bushing having its outerendfaced-toprovide a bearlng seat and its inner end conformed to provide 0ppositelydisposed symmetrical spiral surfaces, and aone-plece plughaving a collar-like peripheral flange at its outergendfaced on its inner side to coact With said bearing seat of said bushing, sald plug having opposed lugs at its inner end adapted to; be introduced throughthe saidlongitudinal grooves of said bushing into engagement With the said spiral surfaces thereof, and lock means for said plug and bushing comprising a flange collar on one partand anoverhanging part having a cooperating setscrew disposed to engage back of said collar flange, whereby the bearing faces of said bushing and plugare clamped together y a-rotative movementof'the plug, said plug b'eing-adapted'to receivea Wrench. In witness WhereofI have hereunto set my hand.

' PETER E. MGINTQSH. 

